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Message-ID: <6601abe90912111401t2749bc1en3d8e5b8f81787897@mail.gmail.com>
Date: Fri, 11 Dec 2009 14:01:48 -0800
From: Curt Wohlgemuth <curtw@...gle.com>
To: Andreas Dilger <adilger@....com>
Cc: ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH] ext4: Ensure zeroout blocks have no dirty metadata
> IIRC, during the discussion of this problem, Ted pointed out that this can
> only happen if the filesystem is running in no-journal mode. Otherwise,
> there are shadow allocation bitmaps that prevent metadata blocks from being
> reallocated until the transaction that released them has committed.
>
> In that case, it makes sense to only do this extra work if the filesystem is
> running in no-journal mode.
Good point, Andreas. I changed this to send in the handle to
ext4_ext_zeroout().
=========================================
This fixes a bug with no journal being used, in which new blocks returned
from an extent created with ext4_ext_zeroout() can have dirty metadata still
associated with them.
Signed-off-by: Curt Wohlgemuth <curtw@...gle.com>
---
This is for the problem I reported on 23 Nov ("Bug in extent zeroout: blocks
not marked as new"). I'm not seeing the corruption with this fix that I was
seeing without it.
diff -uprN orig/fs/ext4/extents.c new/fs/ext4/extents.c
--- orig/fs/ext4/extents.c 2009-12-09 15:09:25.000000000 -0800
+++ new/fs/ext4/extents.c 2009-12-11 13:56:11.000000000 -0800
@@ -2421,7 +2421,8 @@ static void bi_complete(struct bio *bio,
}
/* FIXME!! we need to try to merge to left or right after zero-out */
-static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
+static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex,
+ handle_t *handle)
{
int ret = -EIO;
struct bio *bio;
@@ -2474,9 +2475,28 @@ static int ext4_ext_zeroout(struct inode
submit_bio(WRITE, bio);
wait_for_completion(&event);
- if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+ if (test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+
ret = 0;
- else {
+
+ /* On success, if there is no journal through which
+ * metadata is committed, we need to insure all
+ * metadata associated with each of these blocks is
+ * unmapped. */
+ if (!ext4_handle_valid(handle)) {
+ sector_t block = ee_pblock;
+
+ done = 0;
+ while (done < len) {
+ unmap_underlying_metadata(inode->i_sb->
+ s_bdev,
+ block);
+
+ done++;
+ block++;
+ }
+ }
+ } else {
ret = -EIO;
break;
}
@@ -2532,7 +2552,7 @@ static int ext4_ext_convert_to_initializ
goto out;
/* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
@@ -2583,7 +2603,8 @@ static int ext4_ext_convert_to_initializ
err = ext4_ext_insert_extent(handle, inode, path,
ex3, 0);
if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex,
+ handle);
if (err)
goto fix_extent_len;
ex->ee_block = orig_ex.ee_block;
@@ -2603,7 +2624,7 @@ static int ext4_ext_convert_to_initializ
* implies that we can leak some junk data to user
* space.
*/
- err = ext4_ext_zeroout(inode, ex3);
+ err = ext4_ext_zeroout(inode, ex3, handle);
if (err) {
/*
* We should actually mark the
@@ -2639,7 +2660,7 @@ static int ext4_ext_convert_to_initializ
ext4_ext_mark_uninitialized(ex3);
err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
@@ -2688,7 +2709,7 @@ static int ext4_ext_convert_to_initializ
*/
if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
iblock != ee_block) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
@@ -2757,7 +2778,7 @@ static int ext4_ext_convert_to_initializ
insert:
err = ext4_ext_insert_extent(handle, inode, path, &newex, 0);
if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
@@ -2871,7 +2892,7 @@ static int ext4_split_unwritten_extents(
ext4_ext_mark_uninitialized(ex3);
err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
@@ -2942,7 +2963,7 @@ static int ext4_split_unwritten_extents(
insert:
err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
if (err == -ENOSPC) {
- err = ext4_ext_zeroout(inode, &orig_ex);
+ err = ext4_ext_zeroout(inode, &orig_ex, handle);
if (err)
goto fix_extent_len;
/* update the extent length and mark as initialized */
--
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